1205.2697
Large scale structure in absorption: gas within and around galaxy voids
Tejos, Morris, Crighton, Theuns, Altay, Finn
Properties of HI LyA forest within and around galaxy voids at z<0.1. Find significant excess (>99% cl) of LyA systems at the edges of galaxy voids wrt a random distribution, on 5 Mpc/h scales. No significant difference in the number of systems inside voids. Report differences between both column density and Doppler parameter distributions of Ly-A systems found inside and at the edge of galaxy voids at >98 and >90% CL, respectively. [?] Low density environments (voids) have smaller values for both N_HI and b_HI than higher ones (edge of voids). Consistent with 3 types of Ly-a systems: (1) containing embedded galaxies, and so directly correlated with galaxies ('halo-like') (2) correlated with galaxies only because they lie in the same over dense LSS, and (3) associated with under-dense LSS with a very low auto-correlation amplitude (~random) that are not correlated with luminous galaxies. Latter drive in structures still growing linearly from the primordial density fluctuations inside galaxy voids that have not formed galaxies because of their low densities; estimate 25-30% of the current LyA population account for these absorbers. 'halo-like' absorbers (assuming they must have high column density) account for 12-15%.
No comments:
Post a Comment